Does DUAL Layer Cathode Increase the POWER Density of Lithium-ION Batteries ?

Abstract

Lithium-ion batteries is one of the most popular technological innovations for storing electrical energy also in the automotive field. They have many advantages due to lithium’s high storage capacity to weight ratio. Lithium also has the highest voltage and thus practical best energy density of all metals. One of the problems encountered with lithium-ion batteries in the automotive field is the poor power capability. Optimizing the lithium-ion battery performances is a trade-off between energy and power density. To increase the energy density, we need to increase the electrode density, the thickness and minimize redox inactive components. However, to improve power performance we must increase the electrolyte transport in the electrode, which entails lowering the active material fraction as well as the thickness. Moreover, combining several different active materials individually optimized for high power or high capacity may assist in attaining the optimal performance for a given application.In this project, the main goal is to have an analytical handle on the performance of a cathode which is composed of a double layer LiFePO4 and LiNi1/3 Mn1/3 Co1/3 O2 and compare them to their respective single layer (figure1). We study their behavior separately within the double layer structure using a specific current density and their unique potential windows. For the characterization, we are using galvanostatic cycling, chronoamperometry and scanning electron microscopy to relate the electrode performance to their morphology. We also compared the dual layer performance with that of blended electrodes, i.e. a blended mixture of both materials rather than separate layers (figure1). Figure 1